Continuous casting apparatus



Feb. 6, 1968 R. EASTON 3,367,399

CONTINUOUS CASTING APPARATUS Filed June 16, 1965 I NVENTOR. RUFUS E145TON United States Patent f 3,367,399 CONTINUOUS CASTING APPARATUS RufusEaston, Pittsburgh, Pa., assignor to Koppers Company, Inc., acorporation of Delaware Filed June 16, 1965, Ser. No. 464,285 13 Claims.(Cl. 164-282) ABSTRACT OF THE DISCLOSURE Apparatus for producingcontinuous cast strands of steel includes an arcuate apron structurethat supports and guides the strand along a curved path lying in thevertical plane of the casting mold and subtending a first angle greaterthan 90 lying on one side of the strand, and then along a continuationof the curved path in the same vertical plane that subtends a secondangle less than 90; the angles lying on opposite sides of the strand.

This invention relates to continuous metal casting and, moreparticularly, to improvements in the method and apparatus for continuouscasting of steel.

The continuous casting of metals, and steel in particular, has usuallybeen carried out by flowing molten metal into a vertical casting moldfrom which a continuous strand of cast metal is withdrawn verticallydownward, and cut in the vertical position into the lengths required.This requires high structures. Some casting machines have bent thecasting through 90 degrees after complete solidification, or in somecases even before complete solidification, restraightening at groundlevel, with considerable saving in height.

In the present invention, the casting, which is continuously withdrawnfrom a continuous casting mold, is supported on and guided by an arcuateapron structure disposed adjacently beneath the mold. The supportingroller apron structure guides the casting through an arc ofsubstantially more than 90 and then reverse-curves the casting in theopposite direction through an angle substantially less than 90'; bothangles lying substantially in the vertical plane of the casting. Thevertically disposed mold may have either curved or parallel sides.

For a further understanding of the present invention and for furtheradvantages and features thereof, reference may be made to the followingdescription taken in conjunction with the accompanying drawing whichshows, for the purpose of exemplification, embodiments of the invention.

In the drawing:

FIG. 1 is a schematic elevational View, partly in section, of one typeof continuous casting machine including the present invention; and

FIG. 2 is a schematic elevational view, partly in section, of anothertype of continuous casting machine including the present invention.

Referring to FIG. 1, the continuous casting mold 11 is positioned abovea ground or support level 13. The molten metal 15 enters a conventionaltundish 17 from a conventional ladle 19 and discharges into the verticalplanar walled cavity of mold 11. While not shown, the mold 11 may beoscillated vertically in the usual manner to prevent the casting fromsticking to the walls of the mold. A continuous cast strand 21 is formedwithin the mold 11 and while it is being formed, it is withdrawn andsupported upon a curved roller apron structure 23.

, 3,367,399 Patented Feb. 6, 1968 "ice The apron structure 23 includes aplurality of groups of rollers 25 disposed generally on opposite sidesof the casting, and opposed groups of spray nozzles 27 are arrangedintermediate the groups of rollers 25 in the usual manner.

In accordance with this invention, the rollers 25 are disposed generallyalong concentric arcuate axes 29, 31 which subtend an angle 28 greaterthan Preferably, as shown in FIG. 1, the axes 29, 31 of the rollers 25,and the arcuate axis of the cast strand 21 subtends an angle 28 that isapproximtaely Thereafter, the axis 34 of the strand 21 is substantiallystraight for a short distance 32, in the region between A and B, asshown in FIG. 1. As illustrated in FIG. 1, the portion 32 of the castingis inclined upwardly at an angle of approximately 45 to the horizontalor ground level 13; however, this angular upward inclination may bevaried with any particular installation.

In the region between B and C, as shown in FIG. 1, the curvature of theaxes 34 of the strand 21 and 29, 31 of the rollers, is reversed.Preferably, both the arcuate apron axes 2?, 31, and the arcuate castbillet axis 21, in the region between B and C subtend an anglesubstantially less than 9'0", and preferably about 45 Thereafter, fromthe location marked C, the axis of the cast strand is substantiallyhorizontal. The strand 21 enters a unit 33 which operates both as apinch roll to control the movement of the casting and as a straightenerdevice to straighten the casting in a horizontal position. Aconventional cut-off apparatus 35, which may be either a shears or atorch mechanism sever the strand 21 into individual billets, such as thebillet 37, which are conveyed hence in a conventional manner on a usualrunout conveyor 39.

It is convenient and preferable to support the casting mold 11 and thepinch roll-straightener unit 33 at nearly the same level, if possible.This can be practically accomplished by supporting the unit 33substantially at ground level 13, and by providing a pit or sump 41 inthe ground adjacent to the unit 33 in which the lower portion of thearcuate roller apron structure 23 'is mounted. The mold 11 can then bemounted vertically above the apron structure and only slightly above theelevation of the unit 33.

FIG. 2 illustrates the invention in association with a casting mold 43which has an arcuate mold cavity wherein a curved continuous cast strand45 is formed by molten metal 47 discharging from a tundish 49; themolten metal 47 discharging into the tundish from a conventional ladle51.

In this embodiment, the continuous cast strand 45 is also supported onan arcuate roller structure 53 which is associated with groups ofconventional type spray nozzles 55, and as such is similar to the apronstructure 23 described hereinbefore. The continuous cast strand 45 isbent in a vertical plane in such a manner that its axis 57, subtendingan angle that is greater than 90, continues between A and B in asubstantially straight line that inclines upwardly from a horizontalground or support level 59 at an angle of approximately 45. Between theregion B and C, the curvature of the cast strand 45 is reversed in amanner whereby, when the strand leaves the region C, it enters a unit 61that is similar to the unit 33 which operates both as a pinch roll tocontrol the movement of the casting through the machine and as astraightening device to straighten the casting. The casting 45 thenpasses by a cut-off device 63 by means of which the strand is severed toform billets, one of which is illustrated at 65. The billets 65 arecarried thence on a conventional runout table 67 as mentionedpreviously.

In the embodiment of FIG. 2, the lower portion of the apron structure 53is preferably disposed and supported in a pit or sump 69 in the ground59, in the manner described hereinbetore.

It should be understood that in some installations there may not be asubstantially straight portion in the region between A and B. After thecasting 21 has been curved in one direction, it may thereafter be curvedin a reversed manner substantially continuously. That is to say, theaxis of the cast strand forms a continuous smooth reversing or S-shapedcurve in the region between A and C. In this case, the region B iscoincident with the region A and reverse curvature exists between A andC. This situation may obtain in either or both of the embodiments ofFIG. 1 and FIG. 2.

It will be appreciated by those skilled in the art that by virtue ofusing the curved continuous casting mold 43, the height of the moldabove the support or ground level 59 is considerably less than theembodiment of FIG. 1. In such an installation, the mold 43 may be at, oreven just slightly below, the level of the unit 61, as illustrated inFIG. 2.

While the invention has been described in relation to embodiments inFIGS. 1 and 2, showing an arcuate apron structure that guides thecontinuous cast strand in an are substantially greater than 90 after itleaves the continuous casting mold, it should be understood that thecasting may be formed in accordance with the teachings in my co-pendingapplication, Continuous Metal Casting Method and Apparatus, Serial No.404,236, filed October 16, 1964, now Patent 3,329,199.

In operation of the apparatus of this invention, the molten metal is fedinto the mold from the ladle 19 and the tundish 17 in the customarymanner. The continuous cast strand 21 is started in the usual manner byusing a dummy bar (not shown) to close the bottom of the flow-throughcasting mold 11 and to withdraw the strand from the mold in a continuousmanner. Such a dummy bar may be of the flexible type as shown anddescribed in Patent 2,920,359. The cast strand 21 will be shaped to thecurvature of the mold (with vertical planar sides of FIG. 1, and withcurved sides in the embodiment of FIG. 2) and upon emerging from themold, will be supported upon the arcuate apron structure 23.

When the continuous cast strand 21 emerges from the pinchroll-straightener unit 33, it is substantially straight and is in asubstantially horizontal position. Thereafter, the strand passes by aconventional cut-off device, such as a shears or torch mechanism, andthe strand is severed into billets of preselected length. Such billets,of course, are supported on the usual run-out table and conveyed therebyto other locations.

The use of continuous casting machines in older types of melt shops hasbeen uneconomical because the vertical type of casting machineheretofore available, required so much head room that they could not beinstalled within the existing facility. The present invention, however,includes a low-head continuous casting machine that overcomes thisobjection. The continuous casting machine embodying the presentinvention may be readily and conveniently installed in practically anyexisting melt shop, simply by excavating a pit or sump and installingtherein the lower portion of the arcuate type of apron structure in themanner illustrated schematically in FIG. 1 and FIG. 2.

That continuous casting machines embodying the present invention havemany economical features and advantages should be evident to thoseskilled in the art. Although the foregoing describes, with a certaindegree of particularity, preferred embodiments of the invention by wayof an example, it is understood that the invention 4 is not so limited,but is defined by what is hereinafter claimed.

I claim:

1. A continuous metal casting machine comprising:

(a) a ladle for containing molten steel;

(b) a tundish for receiving and discharging therefrom said molten steel;

(0) a vertically reciprocable flow-through casting mold having a cavitytherein wherein a continuous cast strand is formable when said moltensteel is discharged from said tundish into said cavity;

(cl) an apron structure disposed adacently below said mold forsupporting the casting emerging from the mold, one portion of said apronstructure being for supporting a curved cast strand subtending an anglegreater than and another portion of said apron structure being forsupporting said strand in an arc subtending an angle that issubstantially less than 90, the centers of curvature of said arcs beingcoplanar and on opposite sides of said strand;

(e) spray means for cooling said strand as it emerges from said mold andwhile it is supported by said apron structure;

(f) apparatus operatively engaging said strand for controlling themovement thereof through said machine and straightening said strand;

(g) means for severing into billets said continuous strand after itemerges from said control apparatus; and

(h) means to remove said billets from adjacent said machine.

2. A continuous casting machine comprising in combination:

(a) a ladle containing molten steel;

(b) a tundish for receiving and discharging therefrom said molten steel;

(0) a vertically reciprocable flow-through casting mold having therein acavity wherein a continuous cast strand is formable when said moltensteel is discharged from said tundish into said cavity;

(d) means for continuously withdrawing said strand from said mold;

(e) a structure disposed adjacently below said mold for supporting saidcasting after it emerges from said mold and before it enters saidwithdrawing mechanism, said structure being for supporting the curvedstrand in a substantially vertical plane and in such a manner that oneportion of said strand subtends an angle greater than 90 and an adjacentportion of said strand subtends an angle substantially less than 90,said angles being on opposite sides of said strand and in said verticalplane; and

(f) spray means for cooling said strand while it is supported on saidstructure.

3. In a continuous casting machine the combination comprising:

(a) a vertically reciprocable flow-through casting mold having therein acavity wherein a continuous cast strand is formable from molten steelcontinuously flowing into said cavity;

(b) a structure disposed adjacently below said mold for supporting saidstrand after it emerges from said mold and before it enters saidwithdrawing mechanism, said structure being for supporting the strand ina substantially vertical plane and in such a manner that one portion ofsaid strand subtends an angle greater than 90 and an adjacent portion ofsaid strand subtends an angle substantially less than 90, said anglesbeing on opposite sides of said strand and in said vertical plane; and

(c) means to cool said strand after it emerges from said mold.

4. A continuous casting machine comprising:

(a) a vertically reciprocable flow-through casting mold supported abovea first level wherein a continuous cast strand is formable by pouringthereinto molten steel;

(b) apparatus supported at a second lower lever between said mold leveland said first level and operaand in said vertical plane; and

(b) means to cool said strand while it is supported on said apronstructure.

6. In a continuous casting machine the combination angle substantiallygreater than 90 and so that the axis of a second portion of said strandsubtends an angle substantially less than 90, said angles being onopposite sides of said strand and in said vertical tively engaging saidstrand .for controlling the plane; withdrawal movement thereof throughsaid machine (e) means for supporting said apron structure at a leveland for straightening said strand; below said casting mold with thefirst portion of said (c) an apron structure disposed adjacently belowsaid casting being substantially tangent to a level that is casting moldfor supporting said casting in the region below the level at which saidcasting is discharged between said mold and said control apparatus, saidm from said machine; and structure including means for supporting thecurved (f) spray means for cooling said strand upon emerging strand in asubstantially vertical plane and in such a from said mold. manner thatone portion of said strand subtends an 9. The invention set forth inclaim 8 wherein: angle greater than 90 and an adjacent portion of (a)the tangent level of said first portion of said strand said strandsubtends an angle substantially less than is below said ground level.90, said angles being on opposite sides of said strand 10. A continuousstrand casting apparatus comprising: and in said vertical plane; and (a)a substantially vertical flow-through casting mold ((1) means to coolsaid strand after the same emerges adapted to retain molten steel andform therein a from said mold. continuous cast strand; 5. In acontinuous casting machine including a substan- (b) first means tocontinuously withdraw said strand tially vertical casting mold and astrand withdrawal appafrom said mold; ratus, an apron structurecomprising: (c) second means for supporting said continuous (a) aplurality of groups of rollers arranged adjacently strand with the pathof travel of said strand being to said casting mold for supporting saidstrand exin a substantially vertical plane and a first portion oftending in a vertical plane between said mold and the cast strandsubtending a first angle substantially said strand withdrawal apparatus,in such a manner greater than 90 and an adjacent portion of said castthat one portion of said strand subtends an angle substrand subtending asecond angle, oppositely disposed stantially greater than 90 and anadjacent portion of to said first angle, that is substantially less than90 said strand subtends an angle substantially less than and with thefirst portion of said cast strand being 90, said angles being onopposite sides of said strand 3 substantially tangent to a level that isbelow the level of both the mold and the strand withdrawal means; and

((1) means to cool said strand while it is supported on said secondmeans.

11. In a continuous casting machine including a substantially verticalcasting mold and a strand Withdrawal apparatus, an apron structurecomprising:

including: (a) a vertically reciprocable flow-through casting moldsupported above a first ground level wherein a continous cast strand isforma'ble by pouring thereinto molten steel;

(b) an apron structure for supporting said casting after the same hasemerged from said mold, said apron structure comprising a plurality ofgroups of rollers adapted to maintain the axis of said cast strand in asubstantially vertical plane and in such a manner that the axis of afirst portion of said strand subtends an (a) a plurality of groups ofrollers adjacent said casting mold for supporting said casting extendingin a vertical plane between said mold and said casting withdrawalapparatus in such a manner that one portion of said strand arcuatelysubtends an angle greater than 90 and another spaced apart portion ofsaid casting arcuately subtends an angle less than 90, said angles beingon opposite sides of said cast angle Substantially greater than 90 andso that the strand in said vertical plane, with the portion of said axisof a second portion of said strand subtends an casting between saidarcuate portions extending upangle substantially less than 90, saidangles being wardly f m a horizontal level; and on opposite sides ofsaid strand and in said vertical (b) a plurality f spray nozzles locatednear said plane; and rollers from which cooling fluid emerges to contact(c) means for sup p or Said. apron smicture at a and cool said strand asit emerges from said mold.

Second level below Said castmg mold Wlth the first 12 In a continuouscasting machine the combination portion of said casting beingsubstantially tangent to inclugiing 2121,5 ,;f iififi ffi fjifi i 22 5sald castmg (a) a vertically reciprocable flow-through casting mold (d)means for cooling said strand as it emerges from Supported a first levela,contlnuous said mold. cast strand is formable by pourmg thereintomolten 7. The invention set forth in claim 6 wherein: steel; (a) thetangent level of said first portion of said strand a plurality of groupsTone? adlacent 531d P is below said ground level. for supporting saidcasting exiting therefrom in a 8. A continuous casting machinecomprising: vertical plane, and in such a manner that a first pora ladleadapted to Contain molten Steel; tion of said strand arcuately subtendsan angle a illndish adapted t0 receive and discharge thefegreater than90 and a second spaced apart portion of from Said molten Steel; thestrand arcuately subtends an angle less than 90, a Verticallyreciprocable flow-through Casting mold said angles being on oppositesides of said cast strand having a cavity therein wilerein a continuousF in said vertical plane and with the portion of said Str.and formgblewhen molten Steel flows Into casting between said arcuate portionsextending uplsaldlcavity, said mold belng supported above a first wardfrom a horizontal level;

eve (d) an apron structure for supporting said casting after 7 (6),means coolmg Sald Strand upon exmng from the same has emerged from saidmold, said apron Bald mold Structure comprising a plurality of groups ofrollers (d) means to withdraw said strand continuously from formaintaining the axis of said cast strand in a sub- 531d P stantiallyvertical plane and in such a manner that 13- The lIlVeIltlOIl Set fOfth1n a m 1 2 wh r lni the axis of a first portion of said strand subtendsan 7 (a) said first portion of said strand IS substantially 8 tangent toa level below the level of sa id withdrawal OTHER'REFERENCES meansv RefCited I r Continuous Casting of Steel, Special Report 89, Percy, Lund,Humphries and CO. Ltd., LOl'ldOIl 2,698,467 1/1955 Tarquinee et a1.16489 5 and 2,920,359 V1960 Easton et a1 X Handbook des strangglessens,Alummum Yerlag 2,947,075- 8/ 1960 Schneckenburger et a1.v GmbH, 1958,TS230H47, pp. 450-451.

. 164-283 X 5 31157920 -11/1964 Hess 164 282 X 10 J. SPENCER OVERHOLSER,Primary Examiner,

FOREIGN PATENTS J AQ EA A t 116,378 1/1943 Australia. 3 S L N 123,11712/1946 Australia.

